Incorporation of Zr into Calcium Oxide for CO2 Capture by a Simple and Facile Sol-Gel Method

A series of Zr-doped CaO-based sorbents were synthesized by a simple and facile sol gel method, and sample of Ca/Zr (30:1) exhibited excellent CO2 capture capacity (0.64 g CO2/g sorbent) and favorable stability (up to 18 cycles). The performance of sorbent still remained stable when tested under a high decarbonation temperature of 900 degrees C. The structure-property relationship of the sorbents was explored by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission electron microscope (TEM), and N-2 physisorption measurement, respectively. The favorable CO2 capture characteristics of CaO-based sorbents were attributed to the CaZrO3 nanoparticles, which created an inert barrier preventing the sintering-agglomeration, the nanosize of the particles, optimized pore size distributions, and uniform distribution of Ca and Zr in the sorbent.